The present invention relates to a method for making an electrical connector by means of insert molding.
Electrical connectors made by insert molding feature high precision, reliability, and low labor cost. For example, very high density cable interconnect (VHDCI) connectors with a small pitch of 0.8 mm are made by insert molding. However, during the molding process each terminal must be accurately positioned and suspended within a mold cavity without any positional variation under high a injection of molten plastic. Conventionally, dowel pins are assembled to the mold cavity to position and support terminals. However, this increases manufacturing costs and complicates the configuration of the mold cavity as well as maintenance thereof. For example, a typical Ultra SCSI plug connector includes 68 terminals and the corresponding mold cavity requires 68 dowel pins to support the terminals. Additionally, the terminals are arranged in parallel in two different rows. When the dowel pin is to support the corresponding upper terminal, the corresponding lower terminal provides an offset portion to allow the dowel pin to pass therebetween. Furthermore, the dowel pins rooted within the mold cavity hinder the flow of molten plastic therein, thus shapes of the terminals must be modified to reduce this impact. If a dowel pin is inadvertently removed from the cavity, the corresponding terminal loses its support and alignment resulting in an inappropriate or defective portion thereof. U.S. Pat. No. 5,761,805 issued to Guyer on Jun. 9, 1998 describes such a suggestion.
An objective of this invention is to provide a method for making an electrical connector by means of insert molding wherein alignment of terminals within a mold cavity is achieved by portions of the terminals.
In order to achieve the objective set forth, a method for making an electrical connector comprises the steps of 1) Defining first carrier and first terminal sections along a first material sheet. 2) Defining at least a first pilot hole on the first carrier section and at least first and second terminals alternately arranged on the first terminal section. Each first terminal has a body portion extending between front and rear contact portions. 3) Defining a first terminal core by forming a first bridging rib around the first and second terminals aligned by the first carrier through a first inserting mold. 4) Defining second carrier and second terminal sections along a second material sheet. 5) Defining at least a second pilot hole on the second carrier section and at least third and fourth terminals on the second terminal section. Each terminal has a body portion extending between front and rear contact portions. 6) Defining a second terminal core by forming a second bridging rib around the third and fourth terminals aligned by the second carrier through a second inserting mold. 7) Stacking the first and second terminal cores. 8) Making a third insert molding around the body portions of the first/second terminals and the third/fourth terminals respectively aligned by the first bridging rib and the second bridging rib to finalize the whole connector core.
According to an aspect of the present invention, the rear portions are insulation displacement sections which extend transversely from the body portion.
According to another aspect of the present invention, the first and second terminals have different lengths. The front contact portions of the first and second terminals are arranged on a first common plane and the front contact portions of the third and fourth terminal are arranged on a second common plane parallel to the first common plane.